WO2022148497A1

WO2022148497A1 - Random access method and device, storage medium, terminal, and base station

Info

Publication number: WO2022148497A1
Application number: PCT/CN2022/077028
Authority: WO
Inventors: 雷珍珠
Original assignee: 展讯半导体(南京)有限公司
Priority date: 2021-01-08
Filing date: 2022-02-21
Publication date: 2022-07-14
Also published as: CN114760707A

Abstract

A random access method and device, a storage medium, a terminal, and a base station. The method comprises: during a random access process, transmitting a Msg1 to a network by means of a first uplink carrier, so that the network selects, from a plurality of candidate downlink carriers, a first downlink carrier for transmitting a Msg2, wherein the plurality of candidate downlink carriers do not belong to a same beam / beam group, and the first uplink carrier corresponds to the plurality of candidate downlink carriers; receiving, by means of the first downlink carrier, the Msg2 transmitted by the network; determining a second uplink carrier, and transmitting a Msg3 to the network by means of the second uplink carrier, so that the network determines a second downlink carrier for transmitting a Msg4; and receiving, by means of the second downlink carrier, the Msg4 transmitted by the network. Therefore, the problem of carrier switching during a random access process can be solved.

Description

Random access method and device, storage medium, terminal, and base station

technical field

The present invention relates to the field of communications, and in particular, to a random access method and device, a storage medium, a terminal, and a base station.

Background technique

In an NTN (non terrestrial network, non-terrestrial network) scenario (also called a satellite network), a cell consists of multiple beams. Due to the rapid movement of satellites, user equipment (User Equipment, UE for short) needs to perform beam switching frequently. In the future, IoT devices will be connected through satellite networks, and a set of beam management mechanisms will be required. However, the current terrestrial IoT protocol, namely Narrow Band Internet of Things (NB-IoT)/Enhanced Machine Type Communication (eMTC) does not support beam management mechanisms.

However, in the current communication system, the duration of the random access process is relatively long, and coupled with the rapid movement of the satellite, beam switching, ie carrier switching, occurs when the UE initiates the random access process. In the current protocol, the beam switching problem in the random access process cannot be solved.

SUMMARY OF THE INVENTION

The technical problem solved by the present invention is how to solve the problem of beam switching in the random access process.

In order to solve the above problem, an embodiment of the present invention provides a random access method, the method includes: in the random access process, sending Msg1 to the network through the first uplink carrier, so that the network can select from multiple candidate downlink carriers. Selecting the first downlink carrier for sending Msg2, wherein the multiple candidate downlink carriers do not belong to the same beam/beam group, and the first uplink carrier corresponds to the multiple candidate downlink carriers; receiving the network through the first downlink carrier The sent Msg2; determine the second uplink carrier, and send the Msg3 to the network through the second uplink carrier, so that the network determines the second downlink carrier for sending the Msg4; receive the Msg4 sent by the network through the second downlink carrier.

Optionally, before sending the Msg1 to the network through the first uplink carrier, the method further includes: determining whether a carrier switch occurs after the Msg1 is sent, and if a carrier switch occurs, indicating the first target carrier to the network when sending the Msg1, so that the carrier is switched. The network determines the first downlink carrier according to the first target carrier.

Optionally, there is an association relationship between different preambles and/or ROs and each downlink carrier, the first target carrier is the same carrier as the first downlink carrier, and the network is indicated when sending Msg1. Before beam switching, the method further includes: acquiring the preamble and/or RO associated with the first downlink carrier; indicating the first target carrier to the network when sending Msg1, so that the network determines the first target carrier according to the target carrier. The downlink carrier includes: sending the Msg1 to the network through the acquired preamble and/or the RO, so that the network determines the first downlink carrier according to the acquired preamble and/or the RO.

Optionally, the network configures the association relationship between each downlink carrier and different preambles and/or ROs through system broadcast information or RRC signaling.

Optionally, the first target carrier corresponds to a carrier group, each carrier group includes multiple carriers, and there is an association relationship between different preambles and/or ROs and different carrier groups. Indicating the occurrence of beam switching to the network includes: determining a preamble and/or RO associated with the first target carrier; and indicating to the network that the first target carrier occurs when the Msg1 is sent, including: using the determined preamble and/or The RO sends the Msg1 to the network, so that the network determines the carrier group corresponding to the first target carrier according to the determined preamble and/or the RO, and uses one or more carriers in the determined carrier group as the first carrier group downlink carrier.

Optionally, the network configures the association relationship between each carrier group and different preambles and/or ROs through system broadcast information or RRC signaling.

Optionally, if the number of the first downlink carriers exceeds one, the receiving the Msg2 through the first downlink carrier includes: selecting one carrier from the first downlink carriers, and receiving all the messages through the selected carrier. described Msg2.

Optionally, the selecting a carrier from the first downlink carriers includes: selecting a carrier with the best signal quality from the first downlink carriers.

Optionally, the determining whether carrier switching occurs after sending Msg1 includes: predicting whether carrier switching occurs after sending Msg1 by measuring the candidate downlink carriers or according to satellite ephemeris information and current location information.

Optionally, the Msg2 is further used to indicate whether a carrier switch occurs after the Msg2 is sent or after the Msg3 is sent, and after receiving the Msg2 sent by the network through the first downlink carrier, the method further includes: determining according to the Msg2. Whether carrier switching occurs after sending Msg2 or after sending Msg3; wherein, when carrier switching occurs after sending Msg2, the first downlink carrier corresponds to multiple uplink carriers, and the second uplink carrier is the first downlink carrier The uplink carrier corresponds to one of multiple uplink carriers; when carrier switching occurs after sending Msg2, the second uplink carrier corresponds to multiple downlink carriers, and the second downlink carrier is the second uplink carrier corresponds to multiple downlink carriers one of the carriers.

Optionally, if the Msg2 carries the indication information of the second uplink carrier, the Msg2 indicates that carrier switching occurs after the Msg2 is sent, and the determining the second uplink carrier includes: according to the second uplink carrier The indication information of , determines the second uplink carrier.

Optionally, if the Msg2 carries the indication information of the second downlink carrier, the Msg2 indicates that carrier switching is sent after the Msg3 is sent, and after the Msg3 is sent through the second uplink carrier, the method further includes: according to The indication information of the second downlink carrier determines the second downlink carrier.

Optionally, before sending the Msg3 to the network through the second uplink carrier, the method further includes: determining whether a carrier switch occurs after the Msg3 is sent, and if a carrier switch occurs, indicating the second target carrier to the network when the Msg3 is sent, So that the network determines the second downlink carrier for sending the Msg4 according to the second target carrier.

Optionally, the second target carrier and the second downlink carrier are the same carrier, and the Msg3 carries the indication information of the second downlink carrier, so that the network can use the indication information of the second downlink carrier according to the Determine the second downlink carrier.

An embodiment of the present invention further provides a random access method, the method includes: in the random access process, sending the Msg1 to the network through the first uplink carrier, so that the network selects the first one to send the Msg2 from a plurality of candidate downlink carriers. A downlink carrier, wherein the multiple candidate downlink carriers do not belong to the same beam/beam group, and the first uplink carrier corresponds to the multiple candidate downlink carriers; the Msg2 sent by the network is received through the first downlink carrier ; determine the second uplink carrier, and send Msg3 to the network through the second uplink carrier, so that the network determines the second downlink carrier for sending Msg4; receive the Msg4 sent by the network through the second downlink carrier.

Optionally, the UE indicates the first target carrier when sending the Msg1, and the selecting the first downlink carrier for sending the Msg2 from multiple candidate downlink carriers includes: determining the first target carrier according to the first target carrier. downlink carrier.

Optionally, there is an association relationship between different preambles and/or ROs and each downlink carrier, the first target carrier is the same carrier as the first downlink carrier, and the receiving UE sends the data through the first uplink carrier. After the Msg1, the method further includes: determining the first downlink carrier according to the preamble and/or the RO for sending the Msg1.

Optionally, the method further includes: configuring for the UE an association relationship between each downlink carrier and different preambles and/or ROs through system broadcast information or RRC signaling.

Optionally, the first target carrier corresponds to a carrier group, each carrier group includes multiple carriers, and there is an association relationship between different preambles and/or ROs and different carrier groups. Selecting the first downlink carrier for sending the Msg2 among the downlink carriers includes: determining a carrier group corresponding to the first target carrier according to the sent Msg1 preamble and/or RO, and assigning one or more of the determined carrier groups to the carrier group. carrier as the first downlink carrier.

Optionally, the method further includes: configuring the association relationship between each carrier group and different preambles and/or ROs through system broadcast information or RRC signaling.

Optionally, the Msg2 is also used to indicate whether a carrier switch occurs after the Msg2 is sent or after the Msg3 is sent; wherein, when the carrier switch occurs after the Msg2 is sent, the first downlink carrier corresponds to multiple uplink carriers, so The second uplink carrier is one of the multiple uplink carriers corresponding to the first downlink carrier; when carrier switching occurs after sending Msg2, the second uplink carrier corresponds to multiple downlink carriers, and the second downlink carrier The second uplink carrier corresponds to one of the multiple downlink carriers.

Optionally, if the Msg2 carries the indication information of the second uplink carrier, the Msg2 indicates that carrier switching is sent after the Msg2 is sent, and the UE determines the first uplink carrier according to the indication information of the second uplink carrier. Two uplink carriers.

Optionally, if the Msg2 carries the indication information of the second downlink carrier, the Msg2 indicates that carrier switching occurs after the Msg3 is sent, and the UE determines the first downlink carrier according to the indication information of the second downlink carrier. Two downlink carriers.

Optionally, if the Msg3 indicates a second target carrier, after receiving the Msg3 sent by the UE through the second uplink carrier, the method further includes: determining a second downlink carrier for sending the Msg4 according to the second target carrier. .

Optionally, the second target carrier and the second downlink carrier are the same carrier, the Msg3 carries the indication information of the second downlink carrier, and the second target carrier to send the Msg4 is determined according to the second target carrier. The second downlink carrier includes: determining the second downlink carrier according to the indication information of the second downlink carrier.

An embodiment of the present invention further provides a random access device, the device includes: a Msg1 sending module, configured to send the Msg1 to the network through the first uplink carrier during the random access process, so that the network can send the Msg1 from multiple candidate downlink carriers to the network. Select the first downlink carrier for sending Msg2, wherein the multiple candidate downlink carriers do not belong to the same beam/beam group, and the first uplink carrier corresponds to the multiple candidate downlink carriers; the Msg2 receiving module is used to pass The first downlink carrier receives the Msg2 sent by the network; the Msg3 sending module is used to determine the second uplink carrier, and sends the Msg3 to the network through the second uplink carrier, so that the network determines the second downlink carrier for sending the Msg4; The Msg4 receiving module is configured to receive the Msg4 sent by the network through the second downlink carrier.

An embodiment of the present invention further provides a random access device, the device includes: a Msg1 receiving module, configured to receive the Msg1 sent by the UE through the first uplink carrier during the random access process; and a Msg2 sending module, configured to receive the Msg1 from multiple Select the first downlink carrier that sends the Msg2 from among the candidate downlink carriers, and send the Msg2 to the UE through the first downlink carrier, so that the UE determines the second uplink carrier, wherein the multiple candidate downlink carriers are The carriers do not belong to the same beam/beam group, and the first uplink carrier corresponds to the multiple candidate downlink carriers; the Msg3 receiving module is used to receive the Msg3 sent by the UE through the second uplink carrier; the Msg4 sending module, used determining the second downlink carrier for sending the Msg4, and sending the Msg4 to the UE through the second downlink carrier.

An embodiment of the present invention further provides a storage medium, on which a computer program is stored, and when the computer program is run by a processor, the steps of any one of the methods are executed.

An embodiment of the present invention further provides a terminal, including a memory and a processor, the memory stores a computer program that can be run on the processor, and the processor executes any one of the above when running the computer program. steps of the method.

An embodiment of the present invention further provides a base station, including a memory and a processor, the memory stores a computer program that can run on the processor, and the processor executes any one of the above when running the computer program. steps of the method.

Compared with the prior art, the technical solutions of the embodiments of the present invention have the following beneficial effects:

The random access method provided by the embodiment of the present invention supports adding a beam management mechanism during the random access process initiated by the UE. Usually, a cell consists of multiple beams/beam groups, and different beams/beam groups correspond to different carriers. This method Beam management is performed by means of carrier switching to solve the problem of beam switching during random access. Further, the limitation of random access initiated by the UE in the satellite system can be effectively alleviated, the capacity of the system can be increased, and the success rate of random access by the UE can be improved.

Further, if the UE undergoes carrier switching after sending the Msg1, it can notify the network through the Msg1 to adjust the first downlink carrier on which the network sends the Msg2.

Further, if the carrier switching occurs after the network sends the Msg2, or the carrier switching occurs after the UE sends the Msg3, the network may indicate to the UE through the Msg2. Alternatively, the UE can also indicate to the network through Msg3 that carrier switching occurs after sending Msg3

Further, in the random access process, whenever the UE undergoes carrier switching, the corresponding carrier switching mechanism can be used to ensure that the UE and the network have the same understanding of the carrier for sending information, thereby improving the success rate of random access. In addition, the solution of the embodiment of the present invention can ensure that the random access process of each UE is not limited by the carrier switching, and can increase the system capacity.

Description of drawings

1 is a schematic diagram of a cell and a beam in a NTN scenario of the prior art;

2 is a schematic diagram of a random access process in the prior art;

3 is a schematic flowchart of a random access method according to an embodiment of the present invention;

4 is a schematic diagram of a first carrier switching according to an embodiment of the present invention;

5 is a schematic diagram of a second type of carrier switching according to an embodiment of the present invention;

6 is a schematic diagram of a third carrier switching according to an embodiment of the present invention;

FIG. 7 is a schematic flowchart of another random access method according to an embodiment of the present invention;

FIG. 8 is a schematic structural diagram of a random access apparatus according to an embodiment of the present invention;

FIG. 9 is a schematic structural diagram of another random access apparatus according to an embodiment of the present invention.

Detailed ways

Specifically, for the multi-carrier mechanism of Narrow Band Internet of Things (NB-IoT): since the NB-IoT single-frequency cell has only a bandwidth of 180 kilohertz (kHz), in addition to NPSS, NSSS and SIB, this bandwidth In addition to the overhead, the remaining traffic channel capacity is very small. In order to support a large number of terminals, multiple frequency points need to be used to improve network capacity. In addition to the anchor carriers (anchor carriers) including NPSS, NSSS and NPBCH, the cell may also include several non-anchor carriers (non-anchor carriers) that do not include NPSS, NSSS and NPBCH. A cell includes one anchor carrier and several non-anchor carriers, the spectrum bandwidth of each carrier is 180kHz, and the maximum spectrum span of all carriers in the cell does not exceed 20MHz.

Anchor carrier: There is only one downlink carrier in a multi-carrier cell that supports both Narrowband Primary Synchronization Signal (NPSS), Narrowband Secondary Synchronization Signal (NSSS), Narrowband Physical Broadcast Channel ( Narrowband Physical Broadcast Channel (NPBCH for short), Narrowband Physical Downlink Control Channel (NPDCCH for short) and Narrowband Physical Downlink Shared Channel (NPDSCH for short) channels. The UE needs to monitor NPSS, NSSS, NPBCH, NPDCCH and NPDSCH information on the anchor carrier.

Non-anchor carrier: In a multi-carrier cell, there may be several downlink carriers that only carry NPDCCH and NPDSCH, but do not carry NPSS, NSSS and NPBCH channels. The UE may perform data transmission on the non-anchor carrier. In addition, before the UE enters the connected state, the network will designate a carrier for subsequent downlink data transmission through Msg4 (please refer to the random access process in FIG. 2 for details). The UE is in an idle state and can perform paging monitoring on the non-anchor carrier.

Please refer to FIG. 1. FIG. 1 is a schematic diagram of a cell and a beam in an NTN scenario in the prior art; in the NTN scenario, a cell consists of multiple beams. Due to the fast movement of satellites, the UE needs to perform beam switching frequently. In the future, when IoT devices are accessed through satellite networks, a set of beam management mechanisms is required (the current terrestrial IoT protocol, ie NB-IoT/eMTC, does not support beam management mechanisms). At present, a relatively possible beam management method is to perform beam management through carrier switching, that is, a cell consists of multiple beams, different beams correspond to different carriers, and beam switching is realized through carrier switching.

In order to ensure the coverage, NB-IoT/eMTC adopts the technology of repeated transmission. The defined maximum number of repeated transmissions for downlink transmission is 2048 times, and the maximum number of repeated transmission times for uplink transmission is 128 times. The actual number of repeated transmissions of PDSCH/PUSCH is dynamically indicated by its corresponding scheduling DCI using a specific bit field. The UE can determine the number of repeated transmissions of PDSCH/PUSCH according to the DCI. The maximum number of repeated transmissions of PDCCH (ie Rmax) is controlled by radio resources ( Radio Resource Control, RRC)/System Information Block (System Information Block, SIB for short) semi-static configuration.

The Random Access (RA) process in NB-IOT is composed of four steps corresponding to the transmission of message 1 (Msg1), message 2 (Msg2), message 3 (Msg3) and message 4 (Msg4). Please refer to FIG. 2, which is a schematic diagram of a random access process in the prior art.

The step corresponding to Msg1 is that the UE sends a preamble (RACH preamble). At present, the maximum number of repeated transmissions sent by Msg1 is 128. Before sending Msg1, the UE will obtain the current cell signal through the Narrow-band Reference Signal (NRS) (the cell signal can use the quality reference signal received power (Reference Signal) Received Power, referred to as RSRP). The UE compares the current cell signal (RSRP value) obtained by measurement with the relevant threshold value configured by the network to determine the current coverage level (CE Level). Among them, different CE Levels correspond to different times of repeated transmission of Msg1. The UE can determine the number of repeated transmissions of msg1 according to the determined CE Level. If the first transmission of Msg1 fails, the terminal will upgrade the CE Level (that is, increase the value of Msg1 Repeat transmission times) and try again until the Msg2 is successfully received or the Msg1 repeated transmission times (or PRACH resources) corresponding to all CE Levels have been tried.

When the base station receives Msg1, it will instruct the UE to send Msg3 resources and related parameters (including subcarrier indication, Msg3 repeated transmission times, modulation and coding strategies ( Modulation and Coding Scheme, referred to as MCS) instructions, etc.). Among them, the RAR of Msg2 is scheduled by the DCI, when the UE receives the Msg2, it first receives the DCI (the DCI is scrambled by the RA-RNTI, and the DCI indicates the transmission parameters of the Msg2-RAR (including the receiving resource location, subcarrier indication, Msg3 repeated transmission times) , MCS indication, etc.)), the UE then receives the Msg2-RAR according to the DCI. In Msg2, it can carry Time Advance (TA), Power Correction (Power Correction), and Uplink (UL) grant. Temporary Cell-Radio Network Temporary Identifier, Referred to as TC-RNTI) and so on.

The UE sends the Msg3 according to the related scheduling information of the Msg3 indicated by the Msg2-RAR. After the UE sends the Msg3, it will use the unique identifier carried in the Msg3 to monitor the PDCCH. After successfully decoding the PDCCH, it will receive the corresponding Msg4 content according to the DCI information carried by the PDCCH. , Msg4 is scheduled by DCI. Among them, Msg3 includes an RRC connection request (RRC connection request), and Msg4 includes a conflict resolution (Contention resolution).

As mentioned in the background art, the beam switching problem in the random access process cannot be solved in the prior art. Beam switching means that the UE switches from one beam/beam group to another beam/beam group.

In order to solve the above problem, an embodiment of the present invention provides a random access method, the method includes: in the random access process, sending Msg1 to the network through the first uplink carrier, so that the network can select from multiple candidate downlink carriers. Selecting the first downlink carrier for sending Msg2, wherein the multiple candidate downlink carriers do not belong to the same beam/beam group, and the first uplink carrier corresponds to the multiple candidate downlink carriers; receiving the network through the first downlink carrier The sent Msg2; determine the second uplink carrier, and send the Msg3 to the network through the second uplink carrier, so that the network determines the second downlink carrier for sending the Msg4; receive the Msg4 sent by the network through the second downlink carrier. Thereby, the problem of beam switching occurring in the random access process can be solved.

In order to make the above objects, features and beneficial effects of the present invention more clearly understood, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, in this embodiment of the present invention, different beams/beam groups correspond to different carriers/carrier sets, and beam switching is implemented by carrier switching.

Please refer to FIG. 3, which is a schematic flowchart of a random access method according to an embodiment of the present invention. The random access method may specifically include the following steps:

Step S301, in the random access process, send Msg1 to the network through the first uplink carrier, so that the network selects the first downlink carrier for sending Msg2 from multiple candidate downlink carriers, wherein the multiple candidate downlink carriers are not belong to the same beam/beam group, and the first uplink carrier corresponds to the multiple candidate downlink carriers;

Step S302, receiving the Msg2 sent by the network through the first downlink carrier;

The first uplink carrier is the uplink carrier for the UE to send the Msg1 to the network. The first downlink carrier is the downlink carrier that the network sends the Msg2 to the UE according to the received Msg1. The first uplink carrier and the first downlink carrier may belong to the same beam/beam group, or may belong to different beams/beam groups. Optionally, when a carrier switch occurs after the UE sends Msg1, the first downlink carrier and the first uplink carrier belong to different beams/beam groups; conversely, when the UE does not undergo beam switching after sending Msg1, the first downlink carrier The uplink carrier and the first uplink carrier belong to the same beam/beam group.

The method shown in FIG. 3 is performed by a user equipment (User Equipment, UE for short). Please refer to the random access process in FIG. 2 again. In the random access process, after the network receives the Msg1 sent by the UE, it does not directly The Msg2 is sent to the UE according to the beam/beam group to which the first uplink carrier belongs. Instead, the first downlink carrier is selected from multiple candidate carriers belonging to different beams/beam groups.

Step S303, determining a second uplink carrier, and sending Msg3 to the network through the second uplink carrier, so that the network determines the second downlink carrier for sending Msg4;

Step S304, the Msg4 sent by the network is received through the second downlink carrier.

The second uplink carrier is the uplink carrier for the UE to send the Msg3 to the network, and the second downlink carrier is the downlink carrier for the network to send the Msg4 to the UE according to the received Msg3. The second uplink carrier and the second downlink carrier may also belong to the same or different beams/beam groups. Optionally, after the Msg2 is sent, if carrier switching occurs, the UE may also send the Msg2 through a second uplink carrier that belongs to a different beam/beam group from the first downlink carrier. The first uplink carrier is associated with multiple downlink carriers, and if the UE undergoes carrier switching after sending the Msg1, the UE may select other uplink carriers associated with the first downlink carrier as the first downlink carrier.

During the random access procedure, usually only one carrier switch may occur. If the carrier switching occurs after the Msg1 is sent, the network can select a carrier belonging to a different beam/beam group as the first downlink carrier according to step S301, and the first downlink carrier and the designated uplink carrier (ie the second uplink carrier) The correspondence between the first uplink carrier and the multiple candidate downlink carriers, and the correspondence between the first downlink carrier and the designated uplink carrier may be configured by the network side through signaling such as RRC or system broadcast messages. Other occasions for carrier switching are described in detail in the following embodiments.

The method shown in Figure 3 supports adding a beam management mechanism during the random access process initiated by the UE. Usually, a cell consists of multiple beams/beam groups, and different beams/beam groups correspond to different carriers. To solve the problem of beam switching in the random access process, beam management is carried out. Further, the limitation of random access initiated by the UE in the satellite system can be effectively alleviated, the capacity of the system can be increased, and the success rate of random access by the UE can be improved.

In an embodiment, before sending the Msg1 to the network through the first uplink carrier in step S301 in FIG. 3 , the method further includes: determining whether a carrier switch occurs after the Msg1 is sent, and if a carrier switch occurs, sending the Msg1 to The network indicates the first target carrier, so that the network determines the first downlink carrier according to the first target carrier.

Before the UE initiates random access, that is, before sending Msg1, it can be determined whether carrier switching occurs after sending Msg1, so as to prepare for carrier switching after sending Msg1, and the corresponding carrier after switching (ie the first downlink carrier). ) to receive Msg2, and continue the random access process.

Optionally, the determining whether carrier switching occurs after sending Msg1 includes: predicting whether carrier switching will occur after sending Msg1 by measuring the candidate downlink carriers or according to satellite ephemeris information and current location information.

Specifically, the UE obtains the signal quality of each candidate downlink carrier according to the measurement results of each candidate downlink carrier. If the signal of the downlink carrier belonging to the same beam/beam group as the first uplink carrier is lower than the preset value, the judgment will occur. Beam switching, otherwise no beam switching occurs. Thereby, the UE determines whether carrier switching occurs after sending the Msg1.

Alternatively, the UE can judge the movement track of the satellite according to the satellite ephemeris information, and judge whether the movement of the satellite will occur within a period of time after the sending of Msg1 according to the current geographical position of the UE (that is, the current position information). Beam switching. Thereby, the UE determines whether carrier switching occurs after sending the Msg1.

It should be noted that the manner in which the UE determines whether to transmit carrier switching (ie, beam switching) after sending the Msg1 includes, but is not limited to, the above-mentioned situations, and may also be determined in other manners. For example, the UE can determine whether to send the carrier switch after sending the Msg1 according to its own requirements or according to the network instruction.

When the UE determines that carrier switching occurs after the Msg1 is sent, the UE may indicate to the network a downlink carrier belonging to a different beam/beam group from the first uplink carrier, that is, the first target carrier. Optionally, the first target carrier may correspond to one or more downlink carriers, and if the first target carrier corresponds to multiple downlink carriers, the multiple downlink carriers form a carrier group.

Optionally, if the UE determines that no carrier switching will occur after sending the Msg1, the UE may not indicate the first target carrier, and the UE and the network side transmit the Msg2 according to the existing scheme.

In this embodiment, when the UE side determines that a carrier switch occurs after sending Msg1, the network is notified by indicating the first target carrier, so that the network side can determine the first downlink carrier for sending Msg2 according to the first target carrier.

In one embodiment, there is an association relationship between different preambles and/or ROs and each downlink carrier, the first target carrier is the same carrier as the first downlink carrier, and the first target carrier is the same carrier when sending Msg1. Before instructing beam switching, it also includes: acquiring the preamble and/or RO associated with the first downlink carrier; and indicating the first target carrier to the network when sending Msg1, so that the network determines the target carrier according to the target carrier. The first downlink carrier includes: sending the Msg1 to the network through the acquired preamble and/or the RO, so that the network determines the first downlink carrier according to the acquired preamble and/or the RO.

In this embodiment, the first target carrier corresponds to a single downlink carrier, that is, when the UE sends the Msg1, it directly indicates to the network the first downlink carrier used for sending the Msg2 after carrier switching.

Referring to FIG. 2 again, in the random access process, the UE sends a random access (RACH) preamble (Preamble) in Msg1. The UE may indicate the first target carrier to the network through the preamble and/or a physical random access channel opportunity (RACH Occasion, RO for short) sent by the Msg1. There is an association relationship between pre-defined different preambles and different downlink carriers, the UE indicates different downlink carriers to the network through different preambles, and the indicated downlink carrier is the first target carrier. Alternatively, it is pre-defined that there is an association relationship between different ROs and different downlink carriers, the UE indicates different downlink carriers to the network through different ROs, and the indicated downlink carrier is the first target carrier. Alternatively, it is pre-defined that there is an association relationship between different combinations of preambles and ROs and different downlink carriers, and the UE indicates different downlink carriers to the network through different combinations of preambles and ROs, and the indicated downlink carrier is the first. a target carrier.

That is, the predefined associations between different preambles and different downlink carriers, or the associations between different ROs and different downlink carriers, or the combination of different preambles and ROs and different downlink carriers The association between them is configured for the UE by the network through system broadcast messages (such as SIB, etc.) or RRC signaling.

In a specific example, for the satellite Internet of Things scenario, if the carrier switching may occur after Msg1 is sent, the network configures the association between the first uplink carrier and the downlink carrier through system broadcast information or RRC dedicated signaling. The first uplink carrier is associated with multiple candidate downlink carriers, and the multiple candidate downlink carriers are divided into different beams/beam groups. Secondly, the network also needs to configure the preamble and/or RO corresponding to each candidate downlink carrier through system broadcast information or RRC dedicated signaling, that is, the multiple candidate downlink carriers are respectively associated with different preambles and/or different ROs . The network also needs to configure the uplink carrier associated with each candidate downlink carrier (that is, the carrier that sends Msg3) through system broadcast information or RRC dedicated signaling, that is, the downlink carrier is associated with an uplink carrier. Further, the network configures the downlink carrier. The index of the associated upstream carrier.

The UE determines the above carrier association and the association between the downlink carrier and the preamble and/or RO by receiving system broadcast information or RRC dedicated signaling. Before sending the Msg1, the UE predicts whether carrier switching will occur after sending the Msg1 by measuring the candidate downlink carriers or according to satellite ephemeris information and location information, and determines the switched carrier. When sending the Msg1, the UE selects a specific preamble and/or RO to send the Msg1 according to the prediction result and the determined carrier after switching. When receiving the Msg1, the network determines on which downlink carrier to send the Msg2 according to the preamble and/or RO selected by the UE. The UE determines the uplink carrier for transmitting the Msg3 according to the label of the uplink carrier associated with the Msg2, and the receiving carrier of the Msg4 and the receiving carrier of the Msg2 are the same carrier.

Please refer to FIG. 4. FIG. 4 is a schematic diagram of the first carrier switching according to an embodiment of the present invention. It is assumed that the downlink carriers associated with the uplink carrier U1 are: {D1, D2, D3}, wherein the downlink carrier D1 is associated with the uplink carrier and the uplink carrier U1. The downlink carrier D2 is associated with the uplink carrier U2, and the downlink carrier D3 is associated with the uplink carrier U3. beam1, beam2 and beam3 are three different beams/beam groups, U1/D1 is the carrier corresponding to beam1, U2 and D2 are the carrier corresponding to beam2, and U3 and D3 are the carrier corresponding to beam3. The preambles and/or ROs on the uplink carrier U1 are divided into three groups, the first group of preambles and/or ROs corresponds to the downlink carrier D1 (that is, no carrier switching occurs), and the second group of preambles and/or ROs corresponds to the downlink carrier D2 (ie, carrier switching occurs), and the third group of preambles and/or ROs corresponds to the downlink carrier D3 (ie, carrier switching occurs). As shown in Figure 4, the satellite moves rapidly to the left. The transmission positions of Msg1, Msg2, Msg3 and Msg4 are shown in Figure 4. In the coverage area of beam1, carrier U1 is selected to transmit Msg1, and carrier switching is predicted and the target switching is determined. If the beam/beam group is beam2, the UE selects the downlink carrier D2 corresponding to the preamble and/or RO to send Msg1. When receiving Msg1, the network determines on which downlink carrier to send Msg2 according to the preamble and/or RO selected by the UE (the receiving carrier of Msg2 is associated with the preamble and/or RO), that is, the base station sends Msg2 on carrier D2. The UE determines the uplink carrier for sending the Msg3 according to the label of the uplink carrier associated with the Msg2, that is, the carrier U2 is the uplink carrier for sending the Msg3. The received carrier of Msg4 and the received carrier of Msg2 are the same carrier, that is, the downlink carrier D2.

In one embodiment, the first target carrier corresponds to a carrier group, each carrier group includes multiple carriers, and there is an association relationship between different preambles and/or ROs and different carrier groups. Indicating the occurrence of beam switching to the network when Msg1 includes: determining the preamble and/or RO associated with the first target carrier; and indicating to the network the occurrence of the first target carrier when sending Msg1, including: determining the preamble and/or the RO /or the RO sends the Msg1 to the network, so that the network determines the carrier group corresponding to the first target carrier according to the determined preamble and/or the RO, and uses one or more carriers in the determined carrier group as the The first downlink carrier.

In this embodiment, the first target carrier corresponds to multiple downlink carriers, and the multiple downlink carriers form a carrier group, that is, the UE indicates to the network a carrier group for sending Msg2 after carrier switching when sending Msg1. The network may select one or more downlink carriers from the carrier group corresponding to the first target carrier as the first downlink carrier according to the transmission requirement. Optionally, the UE indicates the first target carrier to the network through a preamble and/or RO, that is, indicates a carrier group.

Optionally, the network configures the association relationship between each carrier group and different preambles and/or ROs through system broadcast information or RRC signaling. For the association relationship between the preamble and/or the RO and the carrier group and the configuration of the association relationship, reference may be made to the description of the association relationship between the preamble and/or the RO and the downlink carrier in the previous embodiment, which will not be repeated here.

As described above, when the first target carrier is a carrier group, the network can select one or more of the carrier group as the first downlink carrier, for example, the network can select all downlink carriers in the carrier group as the first downlink carrier line carrier, etc. At this time, the number of the first downlink carrier exceeds one, and the UE can select one downlink carrier to receive Msg2.

Optionally, the selecting a carrier from the first downlink carriers includes: selecting a carrier with the best signal quality from the first downlink carriers. That is, the UE selects a carrier with the best signal quality among the first downlink carriers to receive Msg2.

In a specific example, in the scenario of satellite Internet of Things, if the carrier switching may occur after Msg1 is sent, the network configures the association between the first uplink carrier and the downlink carrier through system broadcast information or RRC dedicated signaling, that is, Each first uplink carrier is associated with multiple candidate downlink carriers, and the multiple candidate downlink carriers are divided into different beams/beam groups. Secondly, the network also needs to configure the preamble and/or RO corresponding to the occurrence of carrier switching and the non-occurrence of carrier switching through system broadcast information or RRC dedicated signaling. Further, the network configures two sets of preambles and/or ROs, one set of preambles and/or ROs is used to indicate that the network does not switch carriers, and the other set of preambles and/or ROs is used to instruct the network to switch beams. The code and/or RO corresponds to a group of carrier groups, and each carrier group includes multiple downlink carriers. At this time, there is a correspondence between the first group of preambles and/or ROs and the carrier group formed by the downlink carriers included in the current beam/beam group (the beam/beam group corresponding to when Msg1 is sent); the first group of preambles and/or There is a correspondence between the RO and the carrier group composed of other downlink carriers except the current beam/beam group in the candidate downlink carriers. The network also needs to configure the uplink carrier associated with each candidate downlink carrier (that is, the carrier that sends Msg3) through system broadcast information or RRC dedicated signaling, that is, each candidate downlink carrier is associated with an uplink carrier. Further, the network configures downlink carriers. The index of the uplink carrier to which the carrier is associated.

The UE determines the above carrier association and the association between the downlink carrier and the preamble and/or RO by receiving system broadcast information or RRC dedicated signaling. Before sending Msg1, the UE predicts whether beam switching (ie, carrier switching) will occur after sending Msg1 by measuring the candidate downlink carriers or according to satellite ephemeris information and location information. When sending the Msg1, the UE selects a specific preamble and/or RO to send the Msg1 according to the prediction result. When the network receives Msg1, it determines whether beam switching occurs according to the preamble and/or RO selected by the UE. If beam switching occurs for the UE, the network needs to be in all candidates except the downlink candidate carrier corresponding to the current beam/beam group. Msg2 is sent on the carrier.

After the UE sends Msg1, the UE selects a specific downlink carrier (such as a downlink carrier with good signal quality) from the candidate downlink carriers according to the measurement of the candidate downlink carriers or according to satellite ephemeris information and location information as the Msg2 receiving carrier. The UE determines the uplink carrier for sending the Msg3 according to the uplink carrier associated with the Msg2. The received carrier of Msg4 and the received carrier of Msg2 are the same carrier.

Please refer to FIG. 4 again, the network configures two sets of preambles and/or ROs, the first set of preambles and/or ROs is used to instruct the network not to switch beams, and the second set of preambles and/or ROs is used to instruct the network to generate beams switch. As shown in Figure 4, the satellite moves quickly to the left, the UE selects carrier U1 in the coverage area of beam 1 (beam1) to transmit Msg1, and determines to switch to beam 2 (beam2) according to the prediction result, then the UE selects the second group of preambles and/or RO to transmit Msg1, and determine D2 as the receive carrier of Msg2. When receiving Msg1, the network determines that the UE has undergone beam switching according to the preamble and/or RO selected by the UE, and on all candidate downlink carriers except the downlink candidate carrier corresponding to the current beam/beam group (ie D2, D3 carrier) to send Msg2. In addition, the UE determines the uplink carrier used for sending the Msg3 according to the uplink carrier associated with the receiving carrier (ie D2) of the Msg2, that is, the carrier U2 is the uplink carrier for sending the Msg3. The received carrier of Msg4 and the received carrier of Msg2 are the same carrier, that is, the downlink carrier D2.

In another specific embodiment, in the scenario of satellite Internet of Things, if the carrier switching may occur after Msg1 is sent, the network configures the association between the first uplink carrier and the downlink carrier through system broadcast information or RRC dedicated signaling , that is, each first uplink carrier is associated with multiple candidate downlink carriers, and the multiple candidate downlink carriers are divided into different beams/beam groups. The network also needs to configure the uplink carrier associated with each candidate downlink carrier (that is, the carrier that sends Msg3) through system broadcast information or RRC dedicated signaling, that is, each candidate downlink carrier is associated with an uplink carrier. Further, the network configures downlink carriers. The index of the uplink carrier to which the carrier is associated.

The UE determines the above carrier association and downlink carrier by receiving system broadcast information or RRC dedicated signaling. Before sending Msg1, the UE predicts whether beam switching (ie, carrier switching) will occur after sending Msg1 by measuring the candidate downlink carriers or according to satellite ephemeris information and location information, and determines the switched carrier. After sending the Msg1, the UE selects a specific downlink carrier (such as a downlink carrier with good signal quality) as the Msg2 receiving carrier in the candidate downlink carriers according to the prediction result (and the determined carrier after the switch). For the network side, When the network receives Msg1, according to the uplink carrier selected by the UE, it will send Msg2 on all candidate carriers associated with the uplink carrier selected by the UE. The UE determines the uplink carrier for sending Msg3 according to the uplink carrier associated with the Msg2 receiving carrier The received carrier of Msg4 is the same carrier as the received carrier of Msg2.

Please refer to Figure 4 again, the satellite moves quickly to the left, the UE selects the carrier U1 in the coverage area of beam1 to transmit Msg1, and determines that the beam/beam group after switching is beam2 according to the prediction result, then the UE selects the downlink carrier D2 for Msg2. reception. For the network side, after receiving the Msg1, the network will send the Msg2 on all candidate downlink carriers (ie, D1, D2, and D3) associated with the uplink carrier U1. The UE determines, according to the uplink carrier associated with the carrier received by Msg2, the uplink carrier for sending the Msg3, that is, the carrier U2 is the uplink carrier for sending the Msg3. The received carrier of Msg4 and the received carrier of Msg2 are the same carrier, that is, the downlink carrier D2.

In the above-mentioned embodiment, if the UE undergoes carrier switching after sending the Msg1, the UE may notify the network through the Msg1 to adjust the first downlink carrier on which the network sends the Msg2.

In an embodiment, the Msg2 is also used to indicate whether a carrier switch occurs after the Msg2 is sent or after the Msg3 is sent. Please refer to FIG. 3 again. The step S302 in FIG. After the Msg2, it also includes: according to the Msg2, determining whether a carrier switch occurs after the Msg2 is sent or after the Msg3 is sent; wherein, when the carrier switch occurs after the Msg2 is sent, the first downlink carrier corresponds to multiple uplink carriers , the second uplink carrier is one of multiple uplink carriers corresponding to the first downlink carrier; when carrier switching occurs after sending Msg2, the second uplink carrier corresponds to multiple downlink carriers, and the second uplink carrier corresponds to multiple downlink carriers. The downlink carrier is one of multiple downlink carriers corresponding to the second uplink carrier.

If the UE undergoes carrier switching after sending the Msg2, the UE may select another uplink carrier associated with the first downlink carrier as the second uplink carrier. If carrier switching is considered after sending Msg2 or Msg3, multiple corresponding uplink carriers may be associated with the first downlink carrier, and these uplink carriers belong to different beams/beam groups; or, multiple corresponding uplink carriers may be associated with the second uplink carrier The downlink carriers belong to different beams/beam groups. Thereby, the carrier switching requirement can be satisfied.

In addition to the carrier switching occurring after sending Msg1 described in the previous embodiments, carrier switching may also occur after the network sends Msg2 (ie, step S302 ) or after the UE finishes sending Msg3 (ie, step S303 ). Since generally only one carrier switch may occur in a random access process, assuming that the carrier switch occurs after Msg2 or Msg3 is sent, the first downlink carrier selected by the network in step S301 is the same as the first uplink carrier. For the downlink carrier of the beam/beam group, step S301 is completed according to the existing protocol.

Optionally, the network determines whether carrier switching occurs after sending Msg2 or sending Msg3 at least according to the location of the UE, according to satellite ephemeris information, and the strength of the transmitted signal of Msg1. If the network determines that carrier switching occurs after sending Msg2 or sending Msg3, This message is then indicated by Msg2 to inform the UE.

Wherein, the indication information of the second uplink carrier is used to indicate the uplink carrier (ie, the second uplink carrier) on which the Msg3 is transmitted. Optionally, the indication information may be an index (index) of the second uplink carrier. Optionally, a new media access control layer control element (Media Access Control (layer) Control Element, MAC CE for short) or information element may be added in Msg2 to carry the indication information of the second uplink carrier.

Optionally, the second uplink carrier corresponds to a specific downlink carrier (that is, the second downlink carrier), so that the network side can use the second downlink carrier corresponding to the second uplink carrier after receiving the Msg3 sent through the second uplink carrier. Send Msg4. The correspondence between the second uplink carrier and the specific downlink carrier may be configured by the network for the UE through RRC signaling or a system broadcast message.

The indication information of the second downlink carrier is used to indicate the downlink carrier on which the Msg4 is transmitted (ie, the second downlink carrier). Optionally, the indication information may be an index (index) of the second downlink carrier. Optionally, a new media access control layer control element (Media Access Control (layer) Control Element, MAC CE for short) or information element may be added in Msg2 to carry the indication information of the second downlink carrier.

In a specific embodiment, in the scenario of satellite Internet of Things, if considering the possibility of carrier switching of the UE after sending Msg2, the network configures the second downlink carrier and multiple uplink carriers through system broadcast information or RRC dedicated signaling. Correspondingly, each first downlink carrier is associated with multiple candidate Msg3 transmission carriers. In addition, the network also needs to configure the downlink carrier corresponding to each candidate Msg3 transmission carrier through system broadcast information or RRC dedicated signaling (for example, configured by the index of the downlink carrier), these downlink carriers are the carriers used for Msg4 reception. . The network instructs one of the multiple candidate Msg3 transmission carriers as the second uplink carrier through Msg2, that is, Msg2 adds a new MAC CE or information element for carrying the indication information of the second uplink carrier.

The UE determines the above-mentioned inter-carrier association relationship by receiving system broadcast information or RRC dedicated signaling. The UE determines the second uplink carrier for Msg3 transmission by receiving Msg2, and then determines the reception carrier of Msg4, that is, the second downlink carrier, according to the determined downlink carrier associated with the Msg3 transmission carrier.

Referring to FIG. 5, FIG. 5 is a schematic diagram of a second type of carrier switching according to an embodiment of the present invention. For example, it is assumed that the candidate Msg3 transmission carriers associated with downlink carrier D1 are: {U1, U2, U3}, wherein downlink carrier D1 is associated with uplink carrier and uplink carrier U1 is associated, downlink carrier D2 is associated with uplink carrier U2, and downlink carrier D3 is associated with uplink carrier Carrier U3 is associated. Beam1, beam2 and beam3 (beam3) are three different beam/beam groups, U1/D1 is the carrier corresponding to beam1, U2 and D2 are the carrier corresponding to beam2, and U3 and D3 are the carrier corresponding to beam3. As shown in Figure 5, the satellite moves rapidly to the left, and the UE selects carrier U1 (ie, the first uplink carrier) in the coverage area of beam1 to transmit Msg1, and receives Msg2 on the downlink carrier D1 (ie, the first downlink carrier). For the network side, after receiving the Msg1, the network will send the Msg2 on the carrier D1. The UE determines, according to the uplink carrier indicated by the indication information of the second uplink carrier in the Msg2, the uplink carrier for sending the Msg3, that is, the carrier U2 is the uplink carrier for sending the Msg3. Then, the reception carrier of Msg4 is determined according to the determined downlink carrier x associated with the transmission carrier of Msg3, that is, D2 is used for the reception of Msg4.

In a specific embodiment, in the scenario of satellite Internet of Things, if considering the possibility of carrier switching of the UE after sending Msg3, the network configures the second uplink carrier and multiple downlink carriers ( That is, the association relationship of multiple candidate Msg4 receiving carriers). The network instructs, through Msg2, one of the multiple candidate Msg4 receiving carriers as the receiving carrier of Msg4 (that is, the second downlink carrier), that is, Msg2 adds a new MAC CE or cell for carrying the second downlink carrier instruction information. The UE determines the above-mentioned inter-carrier association relationship by receiving system broadcast information or RRC dedicated signaling. The UE determines the carrier for Msg4 reception by receiving Msg2.

Referring to FIG. 6, FIG. 6 is a schematic diagram of a third carrier switching according to an embodiment of the present invention. For example, assuming that the candidate Msg3 transmission carriers associated with downlink carrier D1 are: {U1, U2, U3}, beam1, beam2 and beam3 are three different beams/beam groups, U1/D1 is the carrier corresponding to beam1, and D2 is the corresponding carrier of beam2 The carrier, D3 is the carrier corresponding to beam3. As shown in Figure 5, the satellite moves rapidly to the left, and the UE selects carrier U1 (ie, the first uplink carrier) in the coverage area of beam1 to transmit Msg1, and receives Msg2 on the downlink carrier D1 (ie, the first downlink carrier). For the network side, after receiving the Msg1, the network will send the Msg2 on the carrier D1. The UE determines the downlink carrier for sending the Msg4 according to the uplink carrier indicated by the indication information of the second uplink carrier in the Msg2, and continues to use the carrier U1 as the uplink carrier for sending the Msg3. Then, according to the determined downlink carrier (ie, the second downlink carrier) associated with the determined transmission carrier of Msg3, the reception carrier of Msg4 is determined, that is, D2 is used for the reception of Msg4.

In one embodiment, please refer to FIG. 3 again. Before sending the Msg3 to the network through the second uplink carrier in step S303, the method further includes: determining whether a carrier switch occurs after the Msg3 is sent, and if a carrier switch occurs, sending The second target carrier is indicated to the network at Msg3, so that the network determines the second downlink carrier for sending Msg4 according to the second target carrier.

The second target carrier is the downlink carrier indicated by the UE to the network and used for sending the Msg4. The second target carrier may be one or more downlink carriers.

After the UE receives the Msg2 sent by the network side, the UE can also determine whether the carrier switching occurs after the Msg3 is sent. If the carrier switching occurs, the UE instructs the network in the Msg3 to use the downlink carriers included in other beams/beam groups to send the Msg4. The UE receives Msg4 on the corresponding downlink carrier.

Optionally, the UE predicts whether carrier switching will occur after sending Msg3 by measuring the candidate downlink carriers or according to satellite ephemeris information and current location information. For details, please refer to the relevant description of UE predicting whether carrier switching will occur after sending Msg1. , which will not be repeated here.

Wherein, the indication information of the second downlink carrier is used to indicate the downlink carrier (ie, the second downlink carrier) on which the Msg4 is transmitted. Optionally, the indication information may be an index (index) of the second downlink carrier. Optionally, a new media access control layer control element (Media Access Control (layer) Control Element, MAC CE for short) or information element may be added in Msg3 to carry the indication information of the second downlink carrier.

Optionally, when the second target carrier is multiple carriers, the labels of the multiple carriers can be carried in Msg3; alternatively, multiple carriers belonging to different beams/beam groups can be used as a carrier group, which is established in advance. For the association relationship between different preset identifiers and different carrier groups, the UE may only carry a certain preset identifier in Msg3 to indicate the corresponding carrier group. Further, the association relationship between different preset identifiers and different carrier groups can be configured by the network side to the UE through a system broadcast message or RRC signaling.

In the foregoing embodiment, if the carrier switching occurs after the network sends Msg2, or the carrier switching occurs after the UE sends Msg3, the network may indicate to the UE through Msg2. Alternatively, the UE may also indicate to the network through Msg3 that carrier switching occurs after sending the Msg3.

According to the embodiments corresponding to FIG. 3 to FIG. 6 of the present invention, in the random access process, whenever the UE undergoes carrier switching, the corresponding carrier switching mechanism can be used to ensure that the UE and the network have the same understanding of the carrier for sending information. Thus, the success rate of random access is improved. In addition, the solution of the embodiment of the present invention can ensure that the random access process of each UE is not limited by the carrier switching, and can increase the system capacity.

An embodiment of the present invention further provides a random access method, as shown in FIG. 7 , the method includes:

Step S701, in the random access process, receive the Msg1 sent by the UE through the first uplink carrier;

Step S702, select a first downlink carrier for sending Msg2 from multiple candidate downlink carriers, and send the Msg2 to the UE through the first downlink carrier, so that the UE determines a second uplink carrier, wherein the The multiple candidate downlink carriers do not belong to the same beam/beam group, and the first uplink carrier corresponds to the multiple candidate downlink carriers;

Step S703, receiving the Msg3 sent by the UE through the second uplink carrier;

Step S704, determining a second downlink carrier for sending the Msg4, and sending the Msg4 to the UE through the second downlink carrier.

The random access method described in FIG. 7 is performed by a device on the network side (such as a base station, an access point (AP) for short), and for more details on its working principle and working mode, please refer to FIGS. 3 to 3 6 The relevant description on the network side will not be repeated here.

An embodiment of the present invention further provides a random access apparatus 80, as shown in FIG. 8, the random access apparatus 80 includes:

The Msg1 sending module 801 is configured to send the Msg1 to the network through the first uplink carrier during the random access process, so that the network selects the first downlink carrier for sending the Msg2 from multiple candidate downlink carriers, wherein the multiple candidate downlink carriers The candidate downlink carriers do not belong to the same beam/beam group, and the first uplink carrier corresponds to the multiple candidate downlink carriers;

Msg2 receiving module 802, configured to receive the Msg2 sent by the network through the first downlink carrier;

The Msg3 sending module 803 is configured to determine the second uplink carrier, and send the Msg3 to the network through the second uplink carrier, so that the network determines the second downlink carrier for sending the Msg4;

The Msg4 receiving module 804 is configured to receive the Msg4 sent by the network through the second downlink carrier.

For more information on the working principle and working mode of the apparatus shown in FIG. 8 , reference may be made to the related descriptions in FIGS. 3 to 6 , and details are not repeated here.

An embodiment of the present invention further provides a random access apparatus 90, as shown in FIG. 9, the random access apparatus 90 includes:

The Msg1 receiving module 901 is configured to receive the Msg1 sent by the UE through the first uplink carrier during the random access process;

Msg2 sending module 902, configured to select a first downlink carrier for sending Msg2 from multiple candidate downlink carriers, and send the Msg2 to the UE through the first downlink carrier, so that the UE determines the second uplink carrier , wherein the multiple candidate downlink carriers do not belong to the same beam/beam group, and the first uplink carrier corresponds to the multiple candidate downlink carriers;

A Msg3 receiving module 903, configured to receive the Msg3 sent by the UE through the second uplink carrier;

The Msg4 sending module 904 is configured to determine a second downlink carrier for sending the Msg4, and send the Msg4 to the UE through the second downlink carrier.

For more content about the working principle and working mode of the apparatus shown in FIG. 9 , reference may be made to the related description in FIG. 7 , and details are not repeated here.

An embodiment of the present invention further provides a storage medium, on which a computer program is stored, and when the computer program is run by a processor, the steps of any one of the methods are executed. The storage medium may be a computer-readable storage medium, for example, may include non-volatile memory (non-volatile) or non-transitory (non-transitory) memory, and may also include optical disks, mechanical hard disks, solid-state disks, and the like.

An embodiment of the present invention further provides a terminal, where the terminal may be a UE. The terminal may include a memory and a processor, the memory stores a computer program that can be executed on the processor, and the processor executes the steps of the methods described in FIGS. 3 to 6 when the processor runs the computer program.

An embodiment of the present invention further provides a base station, including a memory and a processor, where the memory stores a computer program that can run on the processor, and the processor executes the method shown in FIG. 7 when the processor runs the computer program A step of.

Specifically, in the embodiment of the present invention, the processor may be a central processing unit (central processing unit, CPU for short), and the processor may also be other general-purpose processors, digital signal processors (digital signal processor, DSP for short) ), application specific integrated circuit (ASIC), off-the-shelf programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

It should also be understood that the memory in the embodiments of the present application may be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory may be read-only memory (ROM for short), programmable read-only memory (PROM for short), erasable programmable read-only memory (EPROM for short) , Electrically Erasable Programmable Read-Only Memory (electrically EPROM, EEPROM for short) or flash memory. Volatile memory may be random access memory (RAM), which acts as an external cache. By way of example and not limitation, many forms of random access memory (RAM) are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous Dynamic random access memory (synchronous DRAM, referred to as SDRAM), double data rate synchronous dynamic random access memory (double data rate SDRAM, referred to as DDR SDRAM), enhanced synchronous dynamic random access memory (enhanced SDRAM, referred to as ESDRAM), Synchronous connection dynamic random access memory (synchlink DRAM, referred to as SLDRAM) and direct memory bus random access memory (direct rambus RAM, referred to as DR RAM).

It should be understood that the term "and/or" in this document is only an association relationship to describe associated objects, indicating that there can be three kinds of relationships, for example, A and/or B, which can mean that A exists alone, and A and B exist at the same time , there are three cases of B alone. In addition, the character "/" in this text indicates that the related objects are an "or" relationship.

The "plurality" in the embodiments of the present application refers to two or more.

The descriptions of the first, second, etc. appearing in the embodiments of the present application are only used for illustration and distinguishing the description objects, and have no order. any limitations of the examples.

The "connection" in the embodiments of the present application refers to various connection modes such as direct connection or indirect connection, so as to realize communication between devices, which is not limited in the embodiments of the present application.

Although the present invention is disclosed above, the present invention is not limited thereto. Any person skilled in the art, without departing from the spirit and scope of the present invention, can easily think of changes or substitutions, and can make various changes and modifications, including the combination of the above-mentioned different functions and implementation steps, including the implementation of software and hardware. The methods are all within the protection scope of the present invention.

Claims

A random access method, characterized in that the method comprises:

In the random access process, Msg1 is sent to the network through the first uplink carrier, so that the network selects the first downlink carrier for sending Msg2 from multiple candidate downlink carriers, wherein the multiple candidate downlink carriers do not belong to the same beam /beam group, the first uplink carrier corresponds to the multiple candidate downlink carriers;

receiving the Msg2 sent by the network through the first downlink carrier;

Determine the second uplink carrier, and send Msg3 to the network through the second uplink carrier, so that the network determines the second downlink carrier for sending Msg4;

The Msg4 sent by the network is received through the second downlink carrier.
The method according to claim 1, wherein before the sending the Msg1 to the network through the first uplink carrier, the method further comprises:

Determine whether carrier switching occurs after sending Msg1, and if carrier switching occurs, indicate the first target carrier to the network when sending Msg1, so that the network determines the first downlink carrier according to the first target carrier.
The method according to claim 2, wherein there is an association relationship between different preambles and/or ROs and respective downlink carriers, the first target carrier is the same carrier as the first downlink carrier, and the first target carrier is the same carrier. Before indicating beam switching to the network when sending Msg1, the above also includes:

acquiring the preamble and/or RO associated with the first downlink carrier;

The indicating the first target carrier to the network when sending the Msg1, so that the network determines the first downlink carrier according to the target carrier, includes:

The Msg1 is sent to the network through the acquired preamble and/or RO, so that the network determines the first downlink carrier according to the acquired preamble and/or RO.
The method according to claim 3, wherein the network configures the association relationship between each downlink carrier and different preambles and/or ROs through system broadcast information or RRC signaling.
The method according to claim 3, wherein the first target carrier corresponds to a carrier group, each carrier group includes multiple carriers, and different preambles and/or ROs exist between different carrier groups The association relationship, when the Msg1 is sent, indicating to the network that beam switching occurs, including:

determining the preamble and/or RO associated with the first target carrier;

The indicating the occurrence of the first target carrier to the network when the Msg1 is sent includes:

The Msg1 is sent to the network through the determined preamble and/or RO, so that the network determines the carrier group corresponding to the first target carrier according to the determined preamble and/or RO, and assigns one of the determined carrier groups or Multiple carriers are used as the first downlink carrier.
The method according to claim 5, wherein the network configures the association relationship between each carrier group and different preambles and/or ROs through system broadcast information or RRC signaling.
The method according to claim 5 or 6, wherein if the number of the first downlink carriers exceeds one, the receiving the Msg2 through the first downlink carrier comprises:

One carrier is selected from the first downlink carriers, and the Msg2 is received through the selected carrier.
The method according to claim 7, wherein the selecting a carrier from the first downlink carriers comprises:

A carrier with the best signal quality is selected from the first downlink carriers.
The method according to claim 2, wherein the determining whether a carrier switch occurs after sending the Msg1 comprises:

By measuring the candidate downlink carriers or according to satellite ephemeris information and current location information, it is predicted whether carrier switching will occur after the Msg1 is sent.
The method according to claim 1, wherein the Msg2 is further used to indicate whether carrier switching occurs after sending the Msg2 or after sending the Msg3, and after receiving the Msg2 sent by the network through the first downlink carrier, Also includes:

According to the Msg2, determine whether carrier switching occurs after the Msg2 is sent or after the Msg3 is sent;

Wherein, when carrier switching occurs after sending Msg2, the first downlink carrier corresponds to multiple uplink carriers, and the second uplink carrier is one of the multiple uplink carriers corresponding to the first downlink carrier;

When a carrier switch occurs after the Msg2 is sent, the second uplink carrier corresponds to multiple downlink carriers, and the second downlink carrier is one of the multiple downlink carriers corresponding to the second uplink carrier.
The method according to claim 10, wherein if the Msg2 carries the indication information of the second uplink carrier, the Msg2 indicates that carrier switching occurs after the Msg2 is sent, and the determining the second uplink carrier, include:

The second uplink carrier is determined according to the indication information of the second uplink carrier.
The method according to claim 10, wherein if the Msg2 carries the indication information of the second downlink carrier, the Msg2 instructs to send carrier switching after the Msg3 is sent, and the second uplink carrier is sent through the Msg2. After the carrier sends Msg3, it also includes:

The second downlink carrier is determined according to the indication information of the second downlink carrier.
The method according to claim 1, wherein before the sending the Msg3 to the network through the second uplink carrier, the method further comprises:

Determine whether carrier switching occurs after sending Msg3, and if carrier switching occurs, indicate the second target carrier to the network when sending Msg3, so that the network determines the second downlink carrier for sending Msg4 according to the second target carrier.
The method according to claim 13, wherein the second target carrier and the second downlink carrier are the same carrier, and the Msg3 carries indication information of the second downlink carrier, so that the network can The indication information of the second downlink carrier determines the second downlink carrier.
A random access method, characterized in that the method comprises:

In the random access process, receive the Msg1 sent by the UE through the first uplink carrier;

Select a first downlink carrier for sending Msg2 from multiple candidate downlink carriers, and send the Msg2 to the UE through the first downlink carrier, so that the UE determines a second uplink carrier, wherein the multiple The candidate downlink carriers do not belong to the same beam/beam group, and the first uplink carrier corresponds to the multiple candidate downlink carriers;

receiving the Msg3 sent by the UE through the second uplink carrier;

A second downlink carrier for sending the Msg4 is determined, and the Msg4 is sent to the UE through the second downlink carrier.
The method according to claim 15, wherein the UE indicates the first target carrier when sending the Msg1, and the selecting the first downlink carrier for sending the Msg2 from multiple candidate downlink carriers comprises:

The first downlink carrier is determined according to the first target carrier.
The method according to claim 16, wherein there is an association relationship between different preambles and/or ROs and respective downlink carriers, the first target carrier is the same carrier as the first downlink carrier, and the first target carrier is the same carrier. After receiving the Msg1 sent by the UE through the first uplink carrier, the method further includes:

The first downlink carrier is determined according to the preamble and/or RO for sending the Msg1.
The method according to claim 17, wherein the method further comprises: configuring the association between each downlink carrier and different preambles and/or ROs for the UE through system broadcast information or RRC signaling.
The method according to claim 16, wherein the first target carrier corresponds to a carrier group, each carrier group includes multiple carriers, and different preambles and/or ROs exist between different carrier groups The association relationship, the selection of the first downlink carrier for sending Msg2 from multiple candidate downlink carriers includes:

A carrier group corresponding to the first target carrier is determined according to the sent Msg1 preamble and/or RO, and one or more carriers in the determined carrier group are used as the first downlink carrier.
The method of claim 19, wherein the method further comprises:

The association between each carrier group and different preambles and/or ROs is configured through system broadcast information or RRC signaling.
The method according to claim 15, wherein the Msg2 is further used to indicate whether carrier switching occurs after sending the Msg2 or after sending the Msg3;

Wherein, when carrier switching occurs after sending Msg2, the first downlink carrier corresponds to multiple uplink carriers, and the second uplink carrier is one of the multiple uplink carriers corresponding to the first downlink carrier;

When a carrier switch occurs after the Msg2 is sent, the second uplink carrier corresponds to multiple downlink carriers, and the second downlink carrier is one of the multiple downlink carriers corresponding to the second uplink carrier.
The method according to claim 21, wherein if the Msg2 carries the indication information of the second uplink carrier, the Msg2 instructs to send a carrier switch after sending the Msg2, and the UE according to the second uplink carrier The indication information of the uplink carrier determines the second uplink carrier.
The method according to claim 21, wherein if the Msg2 carries the indication information of the second downlink carrier, the Msg2 indicates that carrier switching occurs after the Msg3 is sent, and the UE according to the second downlink carrier The indication information of the downlink carrier determines the second downlink carrier.
The method according to claim 15, wherein if the Msg3 indicates a second target carrier, after receiving the Msg3 sent by the UE through the second uplink carrier, the method further comprises:

The second downlink carrier for sending the Msg4 is determined according to the second target carrier.
The method according to claim 24, wherein the second target carrier and the second downlink carrier are the same carrier, the Msg3 carries indication information of the second downlink carrier, and the The second target carrier determines the second downlink carrier for sending Msg4, including:

The second downlink carrier is determined according to the indication information of the second downlink carrier.
A random access device, characterized in that the device comprises:

The Msg1 sending module is configured to send the Msg1 to the network through the first uplink carrier during the random access process, so that the network selects the first downlink carrier for sending the Msg2 from multiple candidate downlink carriers, wherein the multiple candidate downlink carriers The downlink carriers do not belong to the same beam/beam group, and the first uplink carrier corresponds to the multiple candidate downlink carriers;

Msg2 receiving module, configured to receive the Msg2 sent by the network through the first downlink carrier;

The Msg3 sending module is used to determine the second uplink carrier, and send the Msg3 to the network through the second uplink carrier, so that the network determines the second downlink carrier for sending the Msg4;

The Msg4 receiving module is configured to receive the Msg4 sent by the network through the second downlink carrier.
A random access device, characterized in that the device comprises:

The Msg1 receiving module is used to receive the Msg1 sent by the UE through the first uplink carrier during the random access process;

The Msg2 sending module is configured to select a first downlink carrier for sending the Msg2 from multiple candidate downlink carriers, and send the Msg2 to the UE through the first downlink carrier, so that the UE determines the second uplink carrier, Wherein, the multiple candidate downlink carriers do not belong to the same beam/beam group, and the first uplink carrier corresponds to the multiple candidate downlink carriers;

A Msg3 receiving module, configured to receive the Msg3 sent by the UE through the second uplink carrier;

The Msg4 sending module is configured to determine the second downlink carrier for sending the Msg4, and send the Msg4 to the UE through the second downlink carrier.
A storage medium on which a computer program is stored, characterized in that, when the computer program is run by a processor, the method of any one of claims 1 to 14, or the method of any one of claims 15 to 25 is executed. step.
A terminal, comprising a memory and a processor, the memory stores a computer program that can be run on the processor, wherein the processor executes any one of claims 1 to 14 when running the computer program the steps of the method described in item.
A base station, comprising a memory and a processor, the memory stores a computer program that can run on the processor, characterized in that, when the processor runs the computer program, any one of claims 15 to 25 is executed the steps of the method described in item.